[linux-block.git] / net / bridge / br_stp_if.c

/*
 *	Spanning tree protocol; interface code
 *	Linux ethernet bridge
 *
 *	Authors:
 *	Lennert Buytenhek		<buytenh@gnu.org>
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/etherdevice.h>
#include <linux/rtnetlink.h>

#include "br_private.h"
#include "br_private_stp.h"


/* Port id is composed of priority and port number.
 * NB: some bits of priority are dropped to
 *     make room for more ports.
 */
static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
{
	return ((u16)priority << BR_PORT_BITS)
		| (port_no & ((1<<BR_PORT_BITS)-1));
}

#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)

/* called under bridge lock */
void br_init_port(struct net_bridge_port *p)
{
	p->port_id = br_make_port_id(p->priority, p->port_no);
	br_become_designated_port(p);
	p->state = BR_STATE_BLOCKING;
	p->topology_change_ack = 0;
	p->config_pending = 0;
}

/* called under bridge lock */
void br_stp_enable_bridge(struct net_bridge *br)
{
	struct net_bridge_port *p;

	spin_lock_bh(&br->lock);
	mod_timer(&br->hello_timer, jiffies + br->hello_time);
	mod_timer(&br->gc_timer, jiffies + HZ/10);

	br_config_bpdu_generation(br);

	list_for_each_entry(p, &br->port_list, list) {
		if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
			br_stp_enable_port(p);

	}
	spin_unlock_bh(&br->lock);
}

/* NO locks held */
void br_stp_disable_bridge(struct net_bridge *br)
{
	struct net_bridge_port *p;

	spin_lock_bh(&br->lock);
	list_for_each_entry(p, &br->port_list, list) {
		if (p->state != BR_STATE_DISABLED)
			br_stp_disable_port(p);

	}

	br->topology_change = 0;
	br->topology_change_detected = 0;
	spin_unlock_bh(&br->lock);

	del_timer_sync(&br->hello_timer);
	del_timer_sync(&br->topology_change_timer);
	del_timer_sync(&br->tcn_timer);
	del_timer_sync(&br->gc_timer);
}

/* called under bridge lock */
void br_stp_enable_port(struct net_bridge_port *p)
{
	br_init_port(p);
	br_port_state_selection(p->br);
	br_log_state(p);
	br_ifinfo_notify(RTM_NEWLINK, p);
}

/* called under bridge lock */
void br_stp_disable_port(struct net_bridge_port *p)
{
	struct net_bridge *br = p->br;
	int wasroot;

	br_log_state(p);

	wasroot = br_is_root_bridge(br);
	br_become_designated_port(p);
	p->state = BR_STATE_DISABLED;
	p->topology_change_ack = 0;
	p->config_pending = 0;

	br_ifinfo_notify(RTM_NEWLINK, p);

	del_timer(&p->message_age_timer);
	del_timer(&p->forward_delay_timer);
	del_timer(&p->hold_timer);

	br_fdb_delete_by_port(br, p, 0);
	br_multicast_disable_port(p);

	br_configuration_update(br);

	br_port_state_selection(br);

	if (br_is_root_bridge(br) && !wasroot)
		br_become_root_bridge(br);
}

static void br_stp_start(struct net_bridge *br)
{
	int r;
	char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
	char *envp[] = { NULL };

	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
	if (r == 0) {
		br->stp_enabled = BR_USER_STP;
		br_debug(br, "userspace STP started\n");
	} else {
		br->stp_enabled = BR_KERNEL_STP;
		br_debug(br, "using kernel STP\n");

		/* To start timers on any ports left in blocking */
		spin_lock_bh(&br->lock);
		br_port_state_selection(br);
		spin_unlock_bh(&br->lock);
	}
}

static void br_stp_stop(struct net_bridge *br)
{
	int r;
	char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
	char *envp[] = { NULL };

	if (br->stp_enabled == BR_USER_STP) {
		r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
		br_info(br, "userspace STP stopped, return code %d\n", r);

		/* To start timers on any ports left in blocking */
		spin_lock_bh(&br->lock);
		br_port_state_selection(br);
		spin_unlock_bh(&br->lock);
	}

	br->stp_enabled = BR_NO_STP;
}

void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
{
	ASSERT_RTNL();

	if (val) {
		if (br->stp_enabled == BR_NO_STP)
			br_stp_start(br);
	} else {
		if (br->stp_enabled != BR_NO_STP)
			br_stp_stop(br);
	}
}

/* called under bridge lock */
void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
{
	/* should be aligned on 2 bytes for compare_ether_addr() */
	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
	unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
	struct net_bridge_port *p;
	int wasroot;

	wasroot = br_is_root_bridge(br);

	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	memcpy(br->dev->dev_addr, addr, ETH_ALEN);

	list_for_each_entry(p, &br->port_list, list) {
		if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
			memcpy(p->designated_bridge.addr, addr, ETH_ALEN);

		if (!compare_ether_addr(p->designated_root.addr, oldaddr))
			memcpy(p->designated_root.addr, addr, ETH_ALEN);

	}

	br_configuration_update(br);
	br_port_state_selection(br);
	if (br_is_root_bridge(br) && !wasroot)
		br_become_root_bridge(br);
}

/* should be aligned on 2 bytes for compare_ether_addr() */
static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];

/* called under bridge lock */
bool br_stp_recalculate_bridge_id(struct net_bridge *br)
{
	const unsigned char *br_mac_zero =
			(const unsigned char *)br_mac_zero_aligned;
	const unsigned char *addr = br_mac_zero;
	struct net_bridge_port *p;

	/* user has chosen a value so keep it */
	if (br->flags & BR_SET_MAC_ADDR)
		return false;

	list_for_each_entry(p, &br->port_list, list) {
		if (addr == br_mac_zero ||
		    memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
			addr = p->dev->dev_addr;

	}

	if (compare_ether_addr(br->bridge_id.addr, addr) == 0)
		return false;	/* no change */

	br_stp_change_bridge_id(br, addr);
	return true;
}

/* called under bridge lock */
void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
{
	struct net_bridge_port *p;
	int wasroot;

	wasroot = br_is_root_bridge(br);

	list_for_each_entry(p, &br->port_list, list) {
		if (p->state != BR_STATE_DISABLED &&
		    br_is_designated_port(p)) {
			p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
			p->designated_bridge.prio[1] = newprio & 0xFF;
		}

	}

	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	br->bridge_id.prio[1] = newprio & 0xFF;
	br_configuration_update(br);
	br_port_state_selection(br);
	if (br_is_root_bridge(br) && !wasroot)
		br_become_root_bridge(br);
}

/* called under bridge lock */
int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
{
	port_id new_port_id;

	if (newprio > BR_MAX_PORT_PRIORITY)
		return -ERANGE;

	new_port_id = br_make_port_id(newprio, p->port_no);
	if (br_is_designated_port(p))
		p->designated_port = new_port_id;

	p->port_id = new_port_id;
	p->priority = newprio;
	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	    p->port_id < p->designated_port) {
		br_become_designated_port(p);
		br_port_state_selection(p->br);
	}

	return 0;
}

/* called under bridge lock */
int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
{
	if (path_cost < BR_MIN_PATH_COST ||
	    path_cost > BR_MAX_PATH_COST)
		return -ERANGE;

	p->path_cost = path_cost;
	br_configuration_update(p->br);
	br_port_state_selection(p->br);
	return 0;
}

ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
{
	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	       id->prio[0], id->prio[1],
	       id->addr[0], id->addr[1], id->addr[2],
	       id->addr[3], id->addr[4], id->addr[5]);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Spanning tree protocol; interface code
	3	* Linux ethernet bridge
	4	*
	5	* Authors:
	6	* Lennert Buytenhek <buytenh@gnu.org>
	7	*
1da177e4 LT	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License
	10	* as published by the Free Software Foundation; either version
	11	* 2 of the License, or (at your option) any later version.
	12	*/
	13
	14	#include <linux/kernel.h>
6ede2463	15	#include <linux/etherdevice.h>
11dc1f36	16	#include <linux/rtnetlink.h>
1da177e4 LT	17
	18	#include "br_private.h"
	19	#include "br_private_stp.h"
	20
	21
	22	/* Port id is composed of priority and port number.
14f98f25	23	* NB: some bits of priority are dropped to
1da177e4 LT	24	* make room for more ports.
	25	*/
	26	static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
	27	{
9d6f229f	28	return ((u16)priority << BR_PORT_BITS)
1da177e4 LT	29	\| (port_no & ((1<<BR_PORT_BITS)-1));
	30	}
	31
14f98f25	32	#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
14f98f25	33
1da177e4 LT	34	/* called under bridge lock */
	35	void br_init_port(struct net_bridge_port *p)
	36	{
	37	p->port_id = br_make_port_id(p->priority, p->port_no);
	38	br_become_designated_port(p);
	39	p->state = BR_STATE_BLOCKING;
	40	p->topology_change_ack = 0;
	41	p->config_pending = 0;
1da177e4 LT	42	}
	43
	44	/* called under bridge lock */
	45	void br_stp_enable_bridge(struct net_bridge *br)
	46	{
	47	struct net_bridge_port *p;
	48
	49	spin_lock_bh(&br->lock);
	50	mod_timer(&br->hello_timer, jiffies + br->hello_time);
	51	mod_timer(&br->gc_timer, jiffies + HZ/10);
9d6f229f	52
1da177e4 LT	53	br_config_bpdu_generation(br);
	54
	55	list_for_each_entry(p, &br->port_list, list) {
	56	if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
	57	br_stp_enable_port(p);
	58
	59	}
	60	spin_unlock_bh(&br->lock);
	61	}
	62
	63	/* NO locks held */
	64	void br_stp_disable_bridge(struct net_bridge *br)
	65	{
	66	struct net_bridge_port *p;
	67
78872ccb	68	spin_lock_bh(&br->lock);
1da177e4 LT	69	list_for_each_entry(p, &br->port_list, list) {
	70	if (p->state != BR_STATE_DISABLED)
	71	br_stp_disable_port(p);
	72
	73	}
	74
	75	br->topology_change = 0;
	76	br->topology_change_detected = 0;
78872ccb	77	spin_unlock_bh(&br->lock);
1da177e4 LT	78
	79	del_timer_sync(&br->hello_timer);
	80	del_timer_sync(&br->topology_change_timer);
	81	del_timer_sync(&br->tcn_timer);
	82	del_timer_sync(&br->gc_timer);
	83	}
	84
	85	/* called under bridge lock */
	86	void br_stp_enable_port(struct net_bridge_port *p)
	87	{
	88	br_init_port(p);
	89	br_port_state_selection(p->br);
28a16c97	90	br_log_state(p);
4ecb961c	91	br_ifinfo_notify(RTM_NEWLINK, p);
1da177e4 LT	92	}
	93
	94	/* called under bridge lock */
	95	void br_stp_disable_port(struct net_bridge_port *p)
	96	{
28a16c97	97	struct net_bridge *br = p->br;
1da177e4 LT	98	int wasroot;
1da177e4 LT	99
28a16c97	100	br_log_state(p);
1da177e4 LT	101
	102	wasroot = br_is_root_bridge(br);
	103	br_become_designated_port(p);
	104	p->state = BR_STATE_DISABLED;
	105	p->topology_change_ack = 0;
	106	p->config_pending = 0;
	107
4ecb961c	108	br_ifinfo_notify(RTM_NEWLINK, p);
4ecb961c	109
1da177e4 LT	110	del_timer(&p->message_age_timer);
	111	del_timer(&p->forward_delay_timer);
	112	del_timer(&p->hold_timer);
	113
1a620698	114	br_fdb_delete_by_port(br, p, 0);
3fe2d7c7	115	br_multicast_disable_port(p);
1a620698	116
1da177e4 LT	117	br_configuration_update(br);
	118
	119	br_port_state_selection(br);
	120
	121	if (br_is_root_bridge(br) && !wasroot)
	122	br_become_root_bridge(br);
	123	}
	124
9cde0708 SH	125	static void br_stp_start(struct net_bridge *br)
	126	{
	127	int r;
	128	char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
	129	char *envp[] = { NULL };
	130
86313c48	131	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
9cde0708 SH	132	if (r == 0) {
9cde0708 SH	133	br->stp_enabled = BR_USER_STP;
28a16c97	134	br_debug(br, "userspace STP started\n");
9cde0708 SH	135	} else {
9cde0708 SH	136	br->stp_enabled = BR_KERNEL_STP;
28a16c97	137	br_debug(br, "using kernel STP\n");
9cde0708 SH	138
	139	/* To start timers on any ports left in blocking */
	140	spin_lock_bh(&br->lock);
	141	br_port_state_selection(br);
	142	spin_unlock_bh(&br->lock);
	143	}
	144	}
	145
	146	static void br_stp_stop(struct net_bridge *br)
	147	{
	148	int r;
	149	char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
	150	char *envp[] = { NULL };
	151
	152	if (br->stp_enabled == BR_USER_STP) {
1a9180a2	153	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
28a16c97	154	br_info(br, "userspace STP stopped, return code %d\n", r);
9cde0708 SH	155
	156	/* To start timers on any ports left in blocking */
	157	spin_lock_bh(&br->lock);
	158	br_port_state_selection(br);
	159	spin_unlock_bh(&br->lock);
	160	}
	161
	162	br->stp_enabled = BR_NO_STP;
	163	}
	164
	165	void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
	166	{
	167	ASSERT_RTNL();
	168
	169	if (val) {
	170	if (br->stp_enabled == BR_NO_STP)
	171	br_stp_start(br);
	172	} else {
	173	if (br->stp_enabled != BR_NO_STP)
	174	br_stp_stop(br);
	175	}
	176	}
	177
1da177e4	178	/* called under bridge lock */
4505a3ef	179	void br_stp_change_bridge_id(struct net_bridge br, const unsigned char addr)
1da177e4	180	{
19bb3506 EK	181	/* should be aligned on 2 bytes for compare_ether_addr() */
	182	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
	183	unsigned char oldaddr = (unsigned char )oldaddr_aligned;
1da177e4 LT	184	struct net_bridge_port *p;
	185	int wasroot;
	186
	187	wasroot = br_is_root_bridge(br);
	188
	189	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
	190	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
	191	memcpy(br->dev->dev_addr, addr, ETH_ALEN);
	192
	193	list_for_each_entry(p, &br->port_list, list) {
6ede2463	194	if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
1da177e4 LT	195	memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
1da177e4 LT	196
6ede2463	197	if (!compare_ether_addr(p->designated_root.addr, oldaddr))
1da177e4 LT	198	memcpy(p->designated_root.addr, addr, ETH_ALEN);
	199
	200	}
	201
	202	br_configuration_update(br);
	203	br_port_state_selection(br);
	204	if (br_is_root_bridge(br) && !wasroot)
	205	br_become_root_bridge(br);
	206	}
	207
19bb3506 EK	208	/* should be aligned on 2 bytes for compare_ether_addr() */
19bb3506 EK	209	static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
1da177e4 LT	210
1da177e4 LT	211	/* called under bridge lock */
edf947f1	212	bool br_stp_recalculate_bridge_id(struct net_bridge *br)
1da177e4	213	{
19bb3506 EK	214	const unsigned char *br_mac_zero =
19bb3506 EK	215	(const unsigned char *)br_mac_zero_aligned;
1da177e4 LT	216	const unsigned char *addr = br_mac_zero;
	217	struct net_bridge_port *p;
	218
92c0574f SH	219	/* user has chosen a value so keep it */
92c0574f SH	220	if (br->flags & BR_SET_MAC_ADDR)
1459a3cc	221	return false;
92c0574f	222
1da177e4 LT	223	list_for_each_entry(p, &br->port_list, list) {
1da177e4 LT	224	if (addr == br_mac_zero \|\|
554c9a8e	225	memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
1da177e4 LT	226	addr = p->dev->dev_addr;
	227
	228	}
	229
edf947f1	230	if (compare_ether_addr(br->bridge_id.addr, addr) == 0)
	231	return false; /* no change */
	232
	233	br_stp_change_bridge_id(br, addr);
	234	return true;
1da177e4 LT	235	}
	236
	237	/* called under bridge lock */
	238	void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
	239	{
	240	struct net_bridge_port *p;
	241	int wasroot;
	242
	243	wasroot = br_is_root_bridge(br);
	244
	245	list_for_each_entry(p, &br->port_list, list) {
	246	if (p->state != BR_STATE_DISABLED &&
	247	br_is_designated_port(p)) {
	248	p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
	249	p->designated_bridge.prio[1] = newprio & 0xFF;
	250	}
	251
	252	}
	253
	254	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
	255	br->bridge_id.prio[1] = newprio & 0xFF;
	256	br_configuration_update(br);
	257	br_port_state_selection(br);
	258	if (br_is_root_bridge(br) && !wasroot)
	259	br_become_root_bridge(br);
	260	}
	261
	262	/* called under bridge lock */
14f98f25	263	int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
1da177e4	264	{
14f98f25	265	port_id new_port_id;
	266
	267	if (newprio > BR_MAX_PORT_PRIORITY)
	268	return -ERANGE;
1da177e4	269
14f98f25	270	new_port_id = br_make_port_id(newprio, p->port_no);
1da177e4 LT	271	if (br_is_designated_port(p))
	272	p->designated_port = new_port_id;
	273
	274	p->port_id = new_port_id;
	275	p->priority = newprio;
	276	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
	277	p->port_id < p->designated_port) {
	278	br_become_designated_port(p);
	279	br_port_state_selection(p->br);
	280	}
14f98f25	281
14f98f25	282	return 0;
1da177e4 LT	283	}
	284
	285	/* called under bridge lock */
14f98f25	286	int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
1da177e4	287	{
14f98f25	288	if (path_cost < BR_MIN_PATH_COST \|\|
	289	path_cost > BR_MAX_PATH_COST)
	290	return -ERANGE;
	291
1da177e4 LT	292	p->path_cost = path_cost;
	293	br_configuration_update(p->br);
	294	br_port_state_selection(p->br);
14f98f25	295	return 0;
1da177e4 LT	296	}
	297
	298	ssize_t br_show_bridge_id(char buf, const struct bridge_id id)
	299	{
	300	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
	301	id->prio[0], id->prio[1],
	302	id->addr[0], id->addr[1], id->addr[2],
	303	id->addr[3], id->addr[4], id->addr[5]);
	304	}